General Rotating mmf Theory of Squirrel Cage Induction Machines with Non Uniform Air Gap and Several Non Sinusoidally Distributed Windings

A new method is given to study the performances of squirrel cage motors of complex design (non uniform air gap, windings with high space harmonic content). It is based on the analysis of electric circuits with time varying coefficients, rather than on consideration of air gap fluxes. It is shown that this method provides good results. It is the basis of a companion paper devoted to the motor which has been the object of the 1975-1976 IEEE single phase motor calculation and test project.